about a dozen traits. these traits, we think, are partially genetic in origin, not completely, but partially. hopefully, by analyzing these traits, we might be able to say something about the relationships between individuals in the population. for example, you see this hole here over the eye. some vessels passed through that hole. we think that that's, perhaps, partially genetic. on this skeleton -- this is a female -- um... you can see a notch instead. so the vessels are passing through a notch. and that's one variation. there are others. here for example, in this mandible, you can see a groove running along here, but it's covered over by a bridge.